Alpha-Pinene as the Main Component of Ducrosia anethifolia (Boiss) Essential Oil is Responsible for its Effect on Locomotor Activity in Rats

Background: Ducrosia anethifolia (DA) is a medicinal plant traditionally used to treat a wide spectrum of illnesses. DA contains a series of antioxidant compounds, including alpha-pinene, which give it a sedative and relaxing effect. In spite of these effects of DA, the effects of DA essential oil on anxiety and locomotor activity in open field tests have not yet been studied. In the present study, the effects of DA essential oil and its main component of alpha-pinene on locomotor activity and anxiety were studied using open field tests. Objectives: The purpose of this study was to investigate the effects of DA essential oil and its main component, alpha-pinene, on locomotor activity and anxiety behaviors using open field and antioxidant capacity tests in Wistar rats. Methods: Sixty-three adult male Wistar rats (weighing ۲۰۰ - ۲۵۰ g) were divided into ۹ groups: control, positive control (diazepam), essential oil treated groups (۲۵, ۵۰, ۱۰۰, ۲۰۰, and ۵۰۰ mg/kg administered intraperitoneally, (i.p.)) and alpha-pinene groups (۰.۲ and ۰.۴ mg/kg, i.p.). For precisely ۳۰ minutes after each injection in all groups, open field tests were used to assess behaviors such as rearing, line crossing, walling, grooming, and stretched attend posturing. In addition, oxidant and antioxidant parameters (malondialdehyde [MDA] and catalase [CAT]) were assessed in the rats’ temporal lobes. Results: DA (۲۰۰ and ۵۰۰ mg/kg doses) and alpha-pinene (۰.۲ and ۰.۴ mg/kg doses) significantly reduced locomotor activity, whereas doses of ۲۵, ۵۰, and ۱۰۰ mg/kg of DA failed to show such an effect. Treatment with DA and alpha-pinene resulted in a significant decrease in MDA levels and a significant increase in CAT activity in comparison to controls. Conclusions: The results of this study suggest that the main component of DA (alpha-pinene) is responsible for DA’s ability to reduce locomotor activity and anxiety, which is indicative of CNS depressant activity. Moreover, it is possible that some of the motor suppression and sedation effects of the alpha-pinene in DA are due to the antioxidant capacity of this substance. However, further research and clinical evaluations are necessary to isolate and identify the other substances responsible for these activities in DA.

Keywords:

Ducrosia anethifolia (Boiss) , Alpha-Pinen , Locomotor Activity , Anxiety , Oxidative Stress , Rats